To start, wash and cut the onions in large pieces and let soak in a mixture of vinegar and water for about 30 mins. Drain and rinse briefly.

In the meantime, boil the potatoes. Let cool a bit then peel and cube them.

Wash and chop the celery. Drain the pinto beans.

In a large bowl, mix pinto beans, cubed potatoes, the chopped celery and the rinsed onions.

Season with salt, black pepper, extra virgin olive oil and one tablespoon of white balsamic vinegar.

Let rest in the refrigerator for at least one hour (overnight for better results) to blend the flavors before serving.

If using dried beans, soak them overnight covered in water. Drain (by discarding the liquid), wash well and sort the beans before use. When the beans are fully soaked, transfer in a large pot. Cover with 1-2 inches of water (enough to keep them from drying out), don't add salt and bring to boil. Remove any foam that they might produce, then cover and let gently simmer for 1-2 hours depending on the size of the beans. NOTE: You can speed up the soaking process by quickly boiling for 10 minutes the beans in a pot, followed by at least one hour in warm water.